Can Physical Activity Change our Mood Through our Gut?

The gut microbiota are microorganisms or bacteria that reside in our intestinal tract. Everyone has approximately 100 trillion microorganisms within their digestive system! Each person has a unique collection and assortment of these bacteria which are unique as our fingerprints. These gut bacteria play a fundamental role in shaping our metabolism, neuronal, and hormonal (endocrine) systems.

Microorganisms also impact our immune function and if dysfunctional, can contribute to problems such as obesity, diabetes, inflammatory bowel disease or depression. There are many research articles that show that the administration of certain strains of gut bacteria to rodents, results in decreased anxiety and depression.

Gut Microbiota & Your Mood

Research suggests an important role for the gut microbiota in brain development, behaviour and mood. This impact occurs locally at the brain, as well as peripherally through the enteric nervous system, which is a part of the autonomic nervous system that lines the digestive tract and is sometimes referred to as the body’s second brain. Our gut microorganisms secrete a number of chemicals, many of which are the same substances used by our neurons to regulate mood, such as serotonin and dopamine.

The Effect of Physical Activity on Gut Microbiota

Exercise positively affects our mood in many ways, including possibly by modifying our gut bacteria. In a recent article by Evans, they found that exercise reversed the negative effects of a high-fat diet on mice alongside a positive effect on their gut bacteria. Additional research suggests that exercise modulates our gut bacteria in ways that food and diet do not, and that this contributes to positive mood in the animals studied. Alternatively, mood disturbances and fatigue experienced by athletes may be related to a disturbed microbiome, induced by the physical stress of very intense exercise.

By being physically active you can positively impact your mood by altering the composition of another endocrine organ in your body – your gut microbiome! This is just another great reason to be active, so get out there, your gut is depending on you!